axpy

Computes a vector-scalar product and adds the result to a vector.

Description

The axpy routines compute a scalar-vector product and add the result to a vector:

y <- alpha*x+y

where:

  • x and y are vectors of n elements,

  • alpha is a scalar.

API

Syntax

void axpy(queue &exec_queue,
  std::int64_t n,
  T alpha,
  buffer<T,1> &x,
  std::int64_t incx,
  buffer<T,1> &y,
  std::int64_t incy)

axpy supports the following precisions and devices.

T

Devices Supported

float

Host, CPU, and GPU

double

Host, CPU, and GPU

std::complex<float>

Host, CPU, and GPU

std::complex<double>

Host, CPU, and GPU

Input Parameters

exec_queue

The queue where the routine should be executed.

n

Number of elements in vector x.

alpha

Specifies the scalar alpha.

x

Buffer holding input vector x. The buffer must be of size at least (1 + (n 1)*abs(incx)). See Matrix Storage for more details.

incx

Stride of vector x.

y

Buffer holding input vector y. The buffer must be of size at least (1 + (n 1)*abs(incy)). See Matrix Storage for more details.

incy

Stride of vector y.

Output Parameters

y

Buffer holding the updated vector y.

Examples

An example of how to use axpy can be found in the oneMKL installation directory, under:

examples/dpcpp/blas/source/axpy.cpp